[ci][docker]: use matrix to reduce build time & change base image to busybox (#417)

* ci: use matrix to reduce build time

* docker: change base image to busybox

* reuse workflows

* only download ipinfo db on tag pushes

* goreleaser

cmd/dashboard/main.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"time"
+	_ "time/tzdata"
 
 	"github.com/naiba/nezha/cmd/dashboard/controller"
 	"github.com/naiba/nezha/cmd/dashboard/rpc"